#include <QtGui>

#include "codeeditor.h"

CodeEditor::CodeEditor(QWidget *parent) : QPlainTextEdit(parent){
    lineNumberArea = new LineNumberArea(this);

    connect(this, SIGNAL(blockCountChanged(int)), this, SLOT(updateLineNumberAreaWidth(int)));
    connect(this, SIGNAL(updateRequest(QRect,int)), this, SLOT(updateLineNumberArea(QRect,int)));
    connect(this, SIGNAL(cursorPositionChanged()), this, SLOT(highlightCurrentLine()));

    updateLineNumberAreaWidth(0);
    highlightCurrentLine();

    highlighter = new Highlighter(this->document());
}

int CodeEditor::lineNumberAreaWidth(){
    int digits = 1;
    int max = qMax(1, blockCount());
    while (max >= 10) {
        max /= 10;
        ++digits;
    }

    int space = 4 + fontMetrics().width(QLatin1Char('9')) * digits;

    return space;
}

void CodeEditor::updateLineNumberAreaWidth(int /* newBlockCount */){
    setViewportMargins(lineNumberAreaWidth(), 0, 0, 0);
}

void CodeEditor::updateLineNumberArea(const QRect &rect, int dy){
    if (dy)
        lineNumberArea->scroll(0, dy);
    else
        lineNumberArea->update(0, rect.y(), lineNumberArea->width(), rect.height());

    if (rect.contains(viewport()->rect()))
        updateLineNumberAreaWidth(0);
}

void CodeEditor::resizeEvent(QResizeEvent *e){
    QPlainTextEdit::resizeEvent(e);

    QRect cr = contentsRect();
    lineNumberArea->setGeometry(QRect(cr.left(), cr.top(), lineNumberAreaWidth(), cr.height()));
}

void CodeEditor::highlightCurrentLine(){
    QList<QTextEdit::ExtraSelection> extraSelections;

    if (!isReadOnly()) {
        QTextEdit::ExtraSelection selection;

        QColor lineColor = QColor(0x8F, 0xFF, 0x00, 32);

        selection.format.setBackground(lineColor);
        selection.format.setProperty(QTextFormat::FullWidthSelection, true);
        selection.cursor = textCursor();
        selection.cursor.clearSelection();
        extraSelections.append(selection);
    }

    setExtraSelections(extraSelections);
}

void CodeEditor::lineNumberAreaPaintEvent(QPaintEvent *event){
    QPainter painter(lineNumberArea);
    painter.fillRect(event->rect(), QColor(0xEC, 0xE9, 0xD8));

    QTextBlock block = firstVisibleBlock();
    int blockNumber = block.blockNumber();
    int top = (int) blockBoundingGeometry(block).translated(contentOffset()).top();
    int bottom = top + (int) blockBoundingRect(block).height();

	while(block.isValid() && top <= event->rect().bottom()) {
        if(block.isVisible() && bottom >= event->rect().top()){
            QString number = QString::number(blockNumber + 1);
            painter.setPen(QColor(Qt::gray));
            painter.drawText(0, top, lineNumberArea->width(), fontMetrics().height(), Qt::AlignCenter, number);
        }

        block = block.next();
        top = bottom;
        bottom = top + (int) blockBoundingRect(block).height();
        ++blockNumber;
    }
}

void CodeEditor::setFileMode(FileMode mode){
	highlighter->setFileMode(mode);
}
